Primary finding
Probable cause
The separation of a steel long line cable that failed and rebounded from a load of logs into the helicopter's main and tail rotors.
Investigator assessment
Analysis narrative
The operator of the helicopter logging operation reported that a steel long line cable failed while the flight crew was setting a load of logs down. The long line rebounded into the main and tail rotor blades, causing substantial damage to both sets of blades. The flight crew was able to make an immediate and successful emergency landing without further damaging the helicopter.
Source record
Factual narrative
On August 11, 2001, about 1150 Alaska daylight time, a Sikorsky S61A helicopter, N5193Y, operated by Silver Bay Logging, Incorporated, under 14 CFR Part 133, sustained substantial damage when a steel long-line broke while lifting logs. The two airline transport certificated pilots were not injured. The accident occurred on Etolin Island, about 12 miles southwest of Wrangell, Alaska. During a telephone conversation with the NTSB investigator-in-charge on August 14, the director of maintenance for the operator related that an American-made steel cable, approximately 200 feet in length, broke about 60 feet above the load of logs the helicopter was lifting. The 5/8 inch cable contacted the helicopter's main and tail rotor blades. The helicopter was able to make an uneventful emergency landing after the crew detached the remaining cable and felt excessive vibration. Postaccident inspection disclosed substantial damage to the main and tail rotors. Two main rotor blades and the tail rotor blades were replaced.